CN111180533A

CN111180533A - Laminated tile assembly, solar cell and manufacturing method of laminated tile assembly

Info

Publication number: CN111180533A
Application number: CN202010076461.2A
Authority: CN
Inventors: 尹丙伟; 孙俊; 陈登运; 丁二亮; 丁士引; 李岩; 石刚
Original assignee: Chengdu Yefan Science and Technology Co Ltd
Current assignee: Tongwei Solar Hefei Co Ltd
Priority date: 2020-01-23
Filing date: 2020-01-23
Publication date: 2020-05-19
Also published as: WO2021013275A3; WO2021013275A2

Abstract

The invention relates to a laminated tile assembly, a solar cell and a manufacturing method of the laminated tile assembly. The main grid lines on the top surface and/or the bottom surface of the solar cell sheet in the laminated tile assembly are multi-section main grid lines, for any one multi-section main grid line, the second section and the third section extend along a straight line on the surface where the second section and the third section are located, and the first section extends in a direction deviating from the extending direction of the second section and the third section so as to leave a space in the extending direction of the second section and the third section for applying an adhesive; the third section can directly contact the main grid line of the solar cell slice adjacent to the third section, so that the conductive connection between the solar cell slices is realized. According to the scheme provided by the invention, the main grid lines of the solar cells are divided into three regions according to respective functions, so that direct conductive contact among the solar cells can be realized without arranging conductive adhesive, and meanwhile, the requirements of the main grid lines on the efficiency of collecting current and the requirement of saving silver paste of the cell can be met.

Description

Laminated tile assembly, solar cell and manufacturing method of laminated tile assembly

Technical Field

The invention relates to the field of energy, in particular to a laminated tile assembly, a solar cell and a manufacturing method of the laminated tile assembly.

Background

With the increasing consumption of conventional fossil energy such as global coal, oil, natural gas and the like, the ecological environment is continuously deteriorated, and particularly, the sustainable development of the human society is seriously threatened due to the increasingly severe global climate change caused by the emission of greenhouse gases. Various countries in the world make respective energy development strategies to deal with the limitation of conventional fossil energy resources and the environmental problems caused by development and utilization. Solar energy has become one of the most important renewable energy sources by virtue of the characteristics of reliability, safety, universality, long service life, environmental protection and resource sufficiency, and is expected to become a main pillar of global power supply in the future.

In a new energy revolution process, the photovoltaic industry in China has grown into a strategic emerging industry with international competitive advantages. However, the development of the photovoltaic industry still faces many problems and challenges, and the conversion efficiency and reliability are the biggest technical obstacles restricting the development of the photovoltaic industry, while the cost control and the scale-up are economically restricted. The photovoltaic module is taken as a core component of photovoltaic power generation, and the development of high-efficiency modules by improving the conversion efficiency of the photovoltaic module is a necessary trend. Various high efficiency modules, such as shingles, half-sheets, multi-master grids, double-sided modules, etc., are currently emerging on the market. With the application places and application areas of the photovoltaic module becoming more and more extensive, the reliability requirement of the photovoltaic module becomes higher and higher, and particularly, the photovoltaic module with high efficiency and high reliability needs to be adopted in some severe or extreme weather frequent areas.

Under the background of vigorous popularization and use of green solar energy, the shingled assembly utilizes the electrical principle of low current and low loss (the power loss of the photovoltaic assembly is in direct proportion to the square of working current) so as to greatly reduce the power loss of the assembly. And secondly, the inter-cell distance region in the cell module is fully utilized to generate electricity, so that the energy density in unit area is high. In addition, the conventional photovoltaic metal welding strip for the assembly is replaced by the conductive adhesive with the elastomer characteristic at present, the photovoltaic metal welding strip shows higher series resistance in the whole battery, and the stroke of a current loop of the conductive adhesive is far smaller than that of a welding strip, so that the laminated assembly becomes a high-efficiency assembly, and meanwhile, the outdoor application reliability is more excellent than that of the conventional photovoltaic assembly, and the laminated assembly avoids stress damage of the metal welding strip to the interconnection position of the battery and other confluence areas. Especially, under the dynamic (load action of natural world such as wind, snow and the like) environment with alternating high and low temperatures, the failure probability of the conventional assembly which is interconnected and packaged by adopting the metal welding strips is far higher than that of the laminated assembly which is interconnected and cut by adopting the conductive adhesive of the elastomer and packaged by the crystalline silicon battery small pieces.

The current mainstream technology for the shingle assembly uses conductive adhesive to interconnect the cut cells, such as shown in fig. 1, wherein the main grid lines are substantially continuously and unitarily disposed along the edges of the cells, and the cells are electrically connected by conductive adhesive. The conductive adhesive is mainly composed of a conductive phase and a bonding phase. The conductive phase mainly comprises precious metals, such as pure silver particles or particles of silver-coated copper, silver-coated nickel, silver-coated glass and the like, and is used for conducting electricity among solar cells, the particle shape and distribution of the conductive phase are based on the requirement of optimal electricity conduction, and at present, more sheet-shaped or sphere-like combined silver powder with D50 being less than 10um is adopted. The adhesive phase is mainly composed of a high molecular resin polymer having weather resistance, and acrylic resin, silicone resin, epoxy resin, polyurethane, and the like are usually selected in accordance with the adhesive strength and weather resistance. In order to enable the conductive adhesive to achieve low contact resistance, low volume resistivity and high adhesion and maintain long-term excellent weather resistance, a conductive adhesive manufacturer can generally complete the design of a conductive phase and an adhesive phase formula, so that the performance stability of the laminated tile assembly under an initial stage environment corrosion test and long-term outdoor practical application is ensured.

And after being packaged, the battery assembly connected by the conductive adhesive is subjected to environmental erosion in outdoor practical use, for example, high and low temperature alternating expansion and contraction with heat generates relative displacement between the conductive adhesives. The most serious reason is that the current is connected in a virtual way or even disconnected, and the main reason is generally that the materials are combined and then are weak in mutual connection capacity. The weak connection capability mainly shows that a process operation window is needed for the operation of the conductive adhesive in the manufacturing process, and the window is relatively narrow in the actual production process and is very easily influenced by environmental factors, such as the temperature and humidity of an operation place, the time for which the conductive adhesive stays in the air after being coated and the like, so that the conductive adhesive loses activity. Meanwhile, the phenomenon of uneven sizing and missing easily occurs under the conditions of glue dispensing, glue spraying or printing process due to the characteristic change of glue, and great hidden danger is caused to the reliability of products. And the conductive adhesive mainly comprises high polymer resin and a large amount of noble metal powder, so that the cost is high, and the ecological environment is damaged to a certain extent (the production and processing of noble metals have great pollution to the environment). Moreover, the conductive adhesive belongs to a paste, has certain fluidity in the process of gluing or laminating, and is very easy to overflow to cause short circuit of the positive electrode and the negative electrode of the laminated interconnected battery string.

That is to say, for most of the laminated assemblies made by adopting the conductive adhesive bonding mode, the characteristics of weak mutual connection strength exist, the requirement of the manufacturing process on the environment is high, the glue overflow and short circuit are easy to occur in the process, the use cost is high, the production efficiency is low, and the like.

In order to solve these problems, it is necessary to use an adhesive having no conductivity instead of the conductive paste. The solar cells need to have a conductive measure in addition to the conductive adhesive to ensure the conductive connection between the solar cells. How to not influence the current collection of the main grid line on the basis of ensuring the conductive connection between the solar cells and not to damage the structure of the main grid line on the basis of ensuring the effective application of the adhesive is a problem to be solved urgently.

There is thus a need to provide a stack of tiles, a solar cell and a method of manufacturing a stack of tiles that at least partially solves the above mentioned problems.

Disclosure of Invention

The invention aims to provide a laminated tile assembly, a solar cell and a manufacturing method of the laminated tile assembly.

Moreover, as the solar cells can be electrically conducted through the direct contact of the main grid lines, no conductive adhesive is needed, and a series of problems such as short circuit and glue failure possibly caused by the conductive adhesive can be avoided.

According to an aspect of the present invention, there is provided a laminated tile assembly including a plurality of solar cell sheets sequentially arranged in a laminated manner along a first direction and fixed with respect to each other by an adhesive, wherein the solar cell sheets include substrate sheets each having one bus bar disposed on each of top and bottom surfaces thereof, the bus bar on at least one of the top and bottom surfaces being a multi-segment bus bar including a first segment, a third segment, and a second segment connected between the first segment and the third segment, wherein:

the second section and the third section extend along a straight line on the surface thereof, and the first section extends along a direction deviating from the direction in which the second section and the third section extend so as to leave a space in the direction in which the second section and the third section extend for applying the adhesive; and is

The third section can directly contact the main grid line of the solar cell slice adjacent to the third section so as to realize the conductive connection between the solar cell slices.

In one embodiment, the second and third sections are in a direction in which one longitudinal edge of the base sheet extends, the first section being recessed on its surface from the longitudinal edge towards the other longitudinal edge of the base sheet.

In one embodiment, the second and third sections extend close to one longitudinal edge of the base sheet, the first section being recessed on its surface from the direction of extension of the second and third sections further towards the longitudinal edge.

In one embodiment, the first section comprises a central section extending parallel to the second direction and a connecting section connecting the central section and the second section.

In one embodiment, the first, second and third sections have the same width, or the first, second and third sections have a width that is smaller than the width of the third section.

In one embodiment, the width of the first section is less than the width of the third section, and the width of the second section tapers in a direction from the third section to the first section.

In one embodiment, the inboard edge of the second section is flush with the inboard edge of the third section, the outboard edge of the second section approaches towards the inboard edge section forming a tapered width; or

The inner and outer edges of the second section are tapered towards each other to form a tapered width thereof.

In one embodiment, the third section has a height greater than that of the second section, so that there is a space between the second sections of the bus bars facing each other of any pair of adjacent solar cell sheets in a direction perpendicular to the base sheet.

In one embodiment, the thickness of the second section tapers in a direction from the third section to the first section.

In one embodiment, the third section is a solid bar structure.

In one embodiment, a cutout is provided in the third section.

In one embodiment, the hollowed-out portion is a circular hole structure or a triangular hole structure formed on the third section.

In one embodiment, the busbar on the top surface and the bottom surface of the solar cell sheet are both multi-segment busbar, and the length of the third segment on the top surface of the solar cell sheet is not equal to the length of the third segment on the bottom surface of the solar cell sheet.

In one embodiment, the top surface and the bottom surface of each solar cell piece are provided with a plurality of sections of main grid lines, the third section is formed into a sawtooth structure on the surface facing away from the substrate piece, and the third sections facing each other of two adjacent solar cell pieces are contacted with each other in a rack meshing manner.

In one embodiment, the joint height of the contacted third sections of each pair of adjacent solar cell sheets is greater than or equal to the height of the adhesive.

In one embodiment, the main grid lines on one of the top surface and the bottom surface of each solar cell are multi-segment main grid lines, and the main grid lines on the other are multi-segment grid line structures arranged intermittently, wherein in the first direction, the multi-segment grid line structures are at least aligned with the third segments of the multi-segment main grid lines, and the spacing parts between the multi-segment grid line structures are at least aligned with the first segments of the multi-segment grid lines.

In one embodiment, the binder is not electrically conductive.

According to another aspect of the present invention, there is provided a solar cell sheet, a plurality of solar cell sheets being capable of being sequentially arranged in a shingled manner in a first direction and being fixed with respect to each other by an adhesive, each solar cell sheet including a substrate sheet, one bus bar being disposed on each of a top surface and a bottom surface of the substrate sheet, the bus bar on at least one of the top surface and the bottom surface being a multi-segment bus bar, the multi-segment bus bar including a first segment, a third segment, and a second segment connected between the first segment and the third segment, wherein:

the second section and the third section extend along a straight line on the surface thereof, and the first section extends offset from the direction of extension of the second section and the third section so as to leave a space in the direction of extension of the second section and the third section for applying the adhesive; and is

In one embodiment, the width of the first section is less than the width of the third section, and the width of the second section tapers in a direction from the first section to the third section.

In one embodiment, the third section is a solid bar structure.

In one embodiment, a cutout is provided in the third section.

In one embodiment, the surface of the third segment facing away from the base sheet is formed in a zigzag structure, so that the third segments of the grid lines facing each other of two adjacent solar cell sheets are in contact with each other in a rack-and-pinion manner.

In one embodiment, the thickness of the busbar is configured such that the bonding height of the contacted third section of each pair of adjacent solar cell sheets is greater than or equal to the height of the adhesive.

In one embodiment, the bus bars on one of the top surface and the bottom surface are multi-segment bus bars, and the bus bars on the other are intermittently arranged multi-segment bus bar structures, wherein in the first direction, the multi-segment bus bar structures are at least aligned with the third segments of the multi-segment bus bars, and the spacing portions between the multi-segment bus bar structures are at least aligned with the first segments of the multi-segment bus bars.

According to a further aspect of the present invention there is provided a method of manufacturing a laminated assembly according to any one of the preceding aspects, the method comprising the steps of:

manufacturing a plurality of solar cell sheets, wherein the solar cell sheets can be sequentially connected in a tiling mode in a first direction, each solar cell sheet comprises a substrate sheet, each of the substrate sheet is provided with a main grid line on the top surface and the bottom surface, the main grid line on at least one of the top surface and the bottom surface is a multi-section main grid line, the multi-section main grid line comprises a first section, a third section and a second section connected between the first section and the third section, and the method comprises the following steps: the second section and the third section extend along a straight line on the surface thereof, and the first section extends offset from the direction in which the second section and the third section extend to leave a space in the direction in which the second section and the third section extend for applying the adhesive; the third section can directly contact the main grid line of the solar cell slice adjacent to the third section so as to realize conductive connection between the solar cell slices;

applying an adhesive to the spaces of the solar cells left by the first sections;

arranging the plurality of solar cells in a shingled manner along the first direction, fixing the plurality of solar cells to each other such that the third sections of the bus bars facing each other of any two adjacent solar cells are in direct contact.

In one embodiment, the step of manufacturing the plurality of solar cell sheets includes:

pretreating the whole solar cell;

cutting the whole solar cell sheet after the pretreatment into small pieces to form the plurality of solar cell sheets.

In one embodiment, the step of pretreating the whole solar cell sheet comprises:

texturing the surface of the total substrate sheet of the whole solar cell sheet;

growing and depositing an inner passivation layer on the front surface and the back surface of the total substrate sheet;

growing and depositing a middle passivation layer on the inner passivation layer;

and growing and depositing an outer passivation layer on the middle passivation layer.

In one embodiment, the inner passivation layer is deposited by a thermal oxidation method, or laughing gas oxidation, or ozonization, or a nitric acid solution chemical method, and the inner passivation layer is provided as a silicon dioxide film layer; and/or

The middle passivation layer is deposited by a PECVD or ALD layer or a solid target material through a PVD layer method, and is set to be an aluminum oxide film layer or a film layer containing aluminum oxide; and/or

The outer passivation layer is deposited using a PVD, CVD or ALD method.

In one embodiment, the method does not include the step of applying a conductive paste.

According to the invention, the main grid lines of the solar cell pieces are divided into three regions according to respective functions, so that direct conductive contact between the solar cell pieces can be realized without arranging conductive adhesive, and meanwhile, the efficiency requirement of collecting current by the main grid lines and the integrity requirement of the main grid lines can be met.

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present invention, reference should be made to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals in the drawings refer to like parts. It will be appreciated by persons skilled in the art that the drawings are intended to illustrate preferred embodiments of the invention without any limiting effect on the scope of the invention, and that the various components in the drawings are not drawn to scale.

Fig. 1 is a schematic front view of a conventional solar cell;

FIG. 2 is a front view of a shingle assembly in accordance with a preferred embodiment of the present invention;

fig. 3A and 3B are views of the back and front sides, respectively, of a solar cell sheet according to a preferred embodiment of the present invention;

fig. 4 is a partially enlarged view of a portion B in fig. 3;

FIG. 5 is an alternative to FIG. 4, again showing a close-up view of portion B of FIG. 3, as may be realized;

FIG. 6 is another alternative to FIG. 4, again showing a close-up view of portion B of FIG. 3, as may be realized;

FIG. 7 is yet another alternative to FIG. 4, again showing a close-up view of portion B of FIG. 3, as may be implemented;

FIG. 8 is a front view of the solar cell sheet of FIG. 3 after an adhesive has been applied thereto;

fig. 9 is a partially enlarged view of a portion C in fig. 3;

FIG. 10 is an alternative to FIG. 9, again showing a close-up view of section C of FIG. 3, as may be realized;

FIG. 11 is another alternative to FIG. 9, again showing a close-up view of section C of FIG. 3, which is a possible implementation;

3 fig. 3 12 3 is 3a 3 schematic 3 cross 3- 3 sectional 3 view 3 of 3a 3 preferred 3 embodiment 3 taken 3 along 3 line 3a 3- 3a 3 of 3 fig. 32 3. 3

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings. What has been described herein is merely a preferred embodiment in accordance with the present invention and other ways of practicing the invention will occur to those skilled in the art and are within the scope of the invention.

The invention provides a laminated assembly, a solar cell and a method for manufacturing the laminated assembly, and fig. 2 to 12 show several preferred embodiments of the invention.

Figure 2 shows a stack assembly 2 according to a preferred embodiment of the present invention. It should be noted that the "first direction" to be mentioned later may be understood as an arrangement direction of each solar cell in the shingle assembly 2, which is substantially consistent with a width direction of each rectangular solar cell, and the first direction is shown as D1 in fig. 2; the "second direction" may be understood as a direction in which second and third segments (to be described in detail later) of the multi-segment bus bar extend, and the second direction is illustrated by D2 in fig. 3.

The shingle assembly 2 includes a plurality of solar cells 1, and the structure of the bottom surface 25 and the top surface 24 of the solar cells 1 is generally shown in fig. 3A and 3B, respectively. The solar cell sheet 1 includes a base sheet, which is preferably made of silicon. The surface of the base sheet is printed with a plurality of grid lines, which in turn comprise sub-grid lines for collecting current and main grid lines for collecting current, wherein the main grid lines on the top surface of the base sheet are also referred to as positive electrodes and the main grid lines on the bottom surface of the base sheet are also referred to as back electrodes, the positive and back electrodes preferably being made of silver.

Referring to fig. 3B, in the present embodiment, the positive electrode 13 is a multi-segment bus bar including a first segment 131, a third segment 133, and a second segment 132 connected between the first segment 131 and the third segment 133. The second and

third segments

132, 133 extend in a straight line over the top surface 24 of the base sheet, the direction of extension of the second and

third segments

132, 133 is marked as second direction D2, the second direction D2 is substantially perpendicular to the first direction D1, and the first segment 131 extends offset from the direction of extension of the second and

third segments

132, 133, leaving room in the direction of extension of the second and

third segments

132, 133 for the application of adhesive. The third segment 133 can directly contact the bus bars of the solar cell sheets adjacent thereto to realize the conductive connection between the solar cell sheets. The second section 132 is primarily for collecting current from the finger.

In the embodiment shown in fig. 3A, the back electrode 12 is a multi-segment gate line structure disposed discontinuously, instead of a multi-segment main gate line, and the specific structure of the back electrode will be described in detail later.

One embodiment of a positive electrode 13 formed as a multi-segment bus bar is shown in fig. 4. Wherein the second and

third sections

132, 133 extend along one longitudinal edge of the base sheet, while the first section 131 is recessed on the top surface from this longitudinal edge towards the other longitudinal edge of the base sheet. For convenience of description, the longitudinal edge along which the second and

third segments

132 and 133 extend is referred to as a left longitudinal edge and the other longitudinal edge is referred to as a right longitudinal edge, and a direction from the left longitudinal edge toward the right longitudinal edge is shown by D1+ in fig. 4, it being understood that the first segment 131 is recessed inward from the second and

third segments

132 and 133 in the direction D1 +. In this way, the first portion 131 extends relative to the direction of extension of the second portion 132 and the third portion 133, thereby leaving room for the adhesive on the second portion 132 and the third portion 133. The state in which the adhesive 4 is applied to the solar cell sheet at the reserved space is shown in fig. 8.

Further, with continued reference to fig. 4, the first segment 131 comprises a central segment 131a and two connecting segments 131b, wherein the central segment 131a extends parallel to the second direction D2 and the connecting segments 131b connect between the central segment 131a and the second segment 132. In this embodiment, the central segment 131a and the connecting segment 131b are both straight segments, but in other embodiments not shown, the first segment may be an arcuate segment.

On the other hand, with continued reference to fig. 4, the second segment 132 and the first segment 131 have a smaller width than the third segment 133. This is because the narrow grid lines can effectively complete the current collection, and the grid line portions for conducting the current to another solar cell need to have a wider thickness, so that the embodiment shown in fig. 4 can ensure both the effective current collection of the second segment 132 and the effective conductive contact of the third segment 133 with another main grid line. In other embodiments, not shown, the first, second and third sections may have equal widths.

Fig. 5 shows another embodiment of the positive electrode 13 formed as a multi-segment bus bar. In this embodiment, the arrangement of the first and

third sections

131 and 133 is the same as in fig. 4, but the width of the second section 132a tapers in the direction from the third section 133 to the first section 131, specifically, the end of the second section 132 connected to the third section 133 has the same width as the third section 133, and the end of the second section 132a connected to the first section 131 has the same width as the first section 131. Also, the inboard edge of the second section 132 is flush with the inboard edge of the third section 133, only the outboard edge of the second section 132 approaches towards the inboard edge section to form its tapered width.

Fig. 6 shows another embodiment of the positive electrode 13 formed as a multi-segment bus bar. In this embodiment, the arrangement of the first and

third sections

131 and 133 is the same as in fig. 5, but the width of the second section 132b tapers in the direction from the third section 133 to the first section 131. In the present embodiment, the end of the second segment 132b connected to the third segment 133 has the same width as the third segment 133, but the end connected to the first segment 131 still has a width greater than that of the first segment. Also, the inner and outer edges of the second section 132b are both close to each other forming a tapered width thereof.

The two settings ensure the smoothness of the overall confluence of the main grid line, and can enhance the strength of the second section and avoid the fracture.

Fig. 7 illustrates yet another embodiment of a multi-segment bus bar. In this embodiment, the second section 132c and the third section 133 are arranged substantially similarly to the several embodiments described above, the second direction D2 being a direction close to one longitudinal edge of the base sheet, and the first section 134 being recessed on the top surface of the base sheet from the direction of extension of the second section 132c and the third section 133 further towards this longitudinal edge, the recessed direction of the first section 134 may be shown by D1-in fig. 7. Such an arrangement may allow the first section 134 to be hidden behind the laminate in the cell overlap area, thereby providing a more aesthetically pleasing appearance to the shingle assembly.

The third segment of the multi-segment bus bar may have various alternative embodiments in addition to the first and second segments as described above.

In the embodiment shown in fig. 9, a hollow portion is disposed on the third section 133a, and the hollow portion is formed in a triangular hole structure, and every three triangular holes are arranged in series along the second direction. In the embodiment shown in fig. 10, a hollowed-out portion is also disposed on the third section 133b, the hollowed-out portion is formed in a circular hole structure, and every five circular holes are sequentially arranged in the second direction. In the embodiment shown in fig. 11, the third section 133 is a solid structure, and the third section 133 smoothly transitions to the second section 132.

As described above and shown in fig. 3, the back electrode 12 of the solar cell may be a multi-segment grid line structure, and each of the multi-segment grid lines 121 of the multi-segment grid line structure is aligned with at least the third segment 133 of the multi-segment main grid line in the first direction, so that the third segment 133 of one of two adjacent solar cells can contact each of the other multi-segment grid lines 121 in the laminated assembly. And, in the first direction, the spacing portions 122 of the multi-segment grid line structure are aligned with at least the first segments 131 of the multi-segment grid lines, so that for adjacent solar cells, a space left by the first segment 131 of one in the second direction can accommodate an adhesive together with the spacing portions 121 of the other.

However, in other embodiments, the positive electrode and the back electrode of each solar cell can be provided as multi-segment bus bars, and fig. 12 shows a connection structure of two adjacent solar cells, in which the back electrode 12a of the solar cell 1 on the top side and the positive electrode 13 of the solar cell 1 on the bottom side are both multi-segment bus bars. In the scheme shown in fig. 12, a region corresponding to the first segment is denoted by S1, a region corresponding to the second segment is denoted by S2, and a region corresponding to the third segment is denoted by S3. It can be seen from the figure that the third sections of the positive electrode 13 and the back electrode 13a are in contact with each other, the contact surfaces of which are marked as conductive contact surfaces 23; the first sections of the positive electrode 13 and the back electrode 12a each reserve a space in which the adhesive 4 is accommodated, the adhesive 4 being applied in the space and the height of the adhesive 4 being less than or equal to the joining height of the two third sections.

The connection between the first section and the third section is a second section, and it can be seen from fig. 12 that the second sections of the two solar cell sheets 1 are not tightly joined but have a spacing 26 in a direction perpendicular to the base sheet, that is, the height of the second section is less than the height of the third section. Preferably, as shown, the thickness of the second section decreases in a direction from the third section to the first section.

Preferably, the adhesive may be made of a non-conductive material, and the adhesive may be, for example, acrylic resin, silicone resin, epoxy resin, polyurethane, etc., and some additives, such as a curing agent, a cross-linking agent, a coupling agent, rubber balls, etc., may be added to form a certain thickness.

In other embodiments not shown in the figures, the solar cell sheet may also have more preferred arrangements. For example, in the case where the multi-segment grid lines are provided on both the top and bottom surfaces of the solar cell sheet, the length of the third segment on the top surface may be greater or less than the length of the third segment on the bottom surface. For another example, the busbar on the top surface and the bottom surface of the solar cell sheet is a multi-section busbar, the surface of the third section facing away from the substrate sheet may be formed into a zigzag structure, and the third sections facing each other of two adjacent solar cell sheets can contact each other in a rack meshing manner.

The invention also provides a manufacturing method for manufacturing the laminated tile assembly, which comprises the following steps:

manufacturing a plurality of solar cell sheets, wherein the solar cell sheets can be sequentially connected in a tiling mode in a first direction, each solar cell sheet comprises a substrate sheet, each of the substrate sheet is provided with a main grid line on the top surface and the bottom surface, the main grid line on at least one of the top surface and the bottom surface is a multi-section main grid line, the multi-section main grid line comprises a first section, a third section and a second section connected between the first section and the third section, and the method comprises the following steps: the second section and the third section extend along a straight line on the surface thereof, and the first section extends offset from the extending direction of the second section and the third section so as to leave a space in the extending direction of the second section and the third section for applying the adhesive; the third section can directly contact the main grid line of the solar cell slice adjacent to the third section so as to realize conductive connection between the solar cell slices;

Further, the step of manufacturing the plurality of solar cell sheets includes:

pretreating the whole solar cell;

Further, the step of pretreating the whole solar cell piece comprises the following steps:

Further, the inner passivation layer is deposited by a thermal oxidation method, a laughing gas oxidation method, an ozonization method or a nitric acid solution chemical method, and is set as a silicon dioxide film layer; and/or

The outer passivation layer is deposited using a PVD, CVD or ALD method.

Preferably, the adhesive is an electrically non-conductive adhesive and the method does not comprise a further step of applying a conductive glue.

The above-described steps can be further specified and optimized. For example, in the texturing step, a single crystal silicon wafer is subjected to surface texturing to obtain a good textured structure, so that the specific surface area is increased, more photons (energy) can be received, meanwhile, the reflection of incident light is reduced, and the subsequent step can comprise a step of cleaning liquid remained in texturing so as to reduce the influence of acidic and alkaline substances on cell junction making. The method also comprises a step of manufacturing a PN junction after the texturing, which comprises the following steps: reacting phosphorus oxychloride with a silicon wafer to obtain phosphorus atoms; after a certain time, phosphorus atoms enter the surface layer of the silicon wafer and permeate and diffuse into the silicon wafer through gaps among the silicon atoms to form an interface of the N-type semiconductor and the P-type semiconductor. And finishing the diffusion and junction making process and realizing the conversion from light energy to electric energy. Because the diffusion junction forms a short circuit channel at the edge of the silicon wafer, photo-generated electrons collected by the front surface of the PN junction flow to the back surface of the PN junction along the region with phosphorus diffused at the edge to cause short circuit, and the PN junction at the edge is removed by etching through plasma, so that the short circuit caused by the edge can be avoided, and in addition, the SE process step can be added. Moreover, a layer of phosphorosilicate glass is formed on the surface of the silicon wafer in the diffusion junction making process, and the influence on the efficiency of the laminated cell is reduced through the phosphorosilicate glass removing process.

Further, laser grooving can be carried out on the silicon wafer after the passivation layer is formed; and sintering after printing the electrodes, reducing the light attenuation of the battery by passing through a light attenuation furnace or an electric injection furnace, and finally testing and grading the battery.

The step of breaking the silicon wafer into a plurality of solar cells is preferably accomplished using a laser cutter. And adding an online laser cutting scribing process to the sintered whole silicon wafer, enabling the sintered whole silicon wafer to enter a scribing detection position for appearance inspection and visually positioning the OK wafer (poor appearance detection can be automatically shunted to the NG position), and freely setting a multi-track scribing machine or presetting a cache stack area according to the online production rhythm so as to realize online continuous feeding operation. And setting relevant parameters of the laser according to the optimal effect of cutting and scribing so as to realize higher cutting speed, narrower cutting heat affected zone and cutting line width, better uniformity, preset cutting depth and the like. And after the automatic cutting is finished, the automatic sheet breaking mechanism of the online laser scribing machine is used for breaking the solar cell sheets at the cutting position to realize the natural separation of the solar cell sheets. It should be noted that the laser cutting surface is far away from the side of the PN junction, so that leakage current caused by damage of the PN junction is avoided, the front and back directions of the battery piece need to be confirmed before the material is cut and fed, and if the front and back directions are opposite, a separate 180-degree reversing device needs to be added.

And finally, after all the solar cells are connected in series to form the laminated assembly, the packaging of the laminated assembly is completed through the links of automatic typesetting and converging, glue film and back plate laying, intermediate inspection, laminating, trimming, framing, intermediate junction box curing, cleaning, testing and the like.

According to the solar cell, the laminated tile assembly and the manufacturing method, when the solar cells are interconnected into the laminated tile assembly, the solar cells are electrically connected through direct contact of the positive electrode and the back electrode, so that conductive adhesive with conductivity can be omitted. Therefore, factors such as environmental erosion, high-low temperature alternation, expansion with heat and contraction with cold and the like which are easy to damage the conductive adhesive can not influence the laminated tile assembly, so that the current virtual connection and the open circuit are not easy to occur. Moreover, as the conductive adhesive is not needed to be arranged, the problems of open circuit of the positive electrode and the negative electrode of the laminated assembly and the like caused by adhesive overflow can be avoided. In addition, because the conductivity of the adhesive is not required, the production cost of the laminated assembly is also reduced.

The foregoing description of various embodiments of the invention is provided for the purpose of illustration to one of ordinary skill in the relevant art. It is not intended that the invention be limited to a single disclosed embodiment. As mentioned above, many alternatives and modifications of the present invention will be apparent to those skilled in the art of the above teachings. Thus, while some alternative embodiments are specifically described, other embodiments will be apparent to, or relatively easily developed by, those of ordinary skill in the art. The present invention is intended to embrace all such alternatives, modifications and variances of the present invention described herein, as well as other embodiments that fall within the spirit and scope of the present invention as described above.

Reference numerals:

solar cell 1

Shingle assembly 2

Top surface 24 of solar cell sheet

Bottom surface 25 of solar cell sheet

Base sheet 11

Positive electrode 13

Back

electrodes

12, 12a

Binder 4

Conductive contact surface 23

First segments

131, 134

Second sections

132, 132a, 132b, 132c

Third segment

133, 133a, 133b

Spacing 26 between the second sections of two solar cells

Center section 131a

Connecting segment 131b

First direction D1

A second direction D2.

Claims

1. A laminated tile assembly comprising a plurality of solar cell sheets sequentially arranged in a laminated tile manner along a first direction and fixed with respect to each other by an adhesive, wherein each of the solar cell sheets comprises a substrate sheet, one bus bar is disposed on each of a top surface and a bottom surface of the substrate sheet, wherein the bus bar on at least one of the top surface and the bottom surface is a multi-segment bus bar, and the multi-segment bus bar comprises a first segment, a third segment, and a second segment connected between the first segment and the third segment, wherein:

the second section and the third section extend along a straight line on the surface thereof, and the first section extends offset from the direction in which the second section and the third section extend to leave a space in the direction in which the second section and the third section extend for applying the adhesive; and is

2. The stack assembly of claim 1, wherein the second segment and the third segment extend along one longitudinal edge of the base sheet, and the first segment is recessed on its face from the longitudinal edge toward the other longitudinal edge of the base sheet.

3. The stack assembly of claim 1, wherein the second segment and the third segment extend proximate to one longitudinal edge of the base sheet, the first segment being recessed on its face from the direction of extension of the second segment and the third segment further toward the longitudinal edge.

4. A stack assembly according to claim 2 or 3, wherein the first section comprises a central section extending parallel to the second direction and a connecting section connecting the central section and the second section.

5. The stack assembly of claim 1, wherein the first, second and third sections are equal in width or have a width less than the width of the third section.

6. The stack assembly of claim 1, wherein the width of the first section is less than the width of the third section, and the width of the second section tapers in a direction from the third section to the first section.

7. The shingle assembly of claim 6,

the inboard edge of the second segment is flush with the inboard edge of the third segment, the outboard edge of the second segment approaches toward the inboard edge segment forming a tapered width; or

The inner and outer edges of the second section are tapered towards each other to form a tapered width.

8. The stack assembly of claim 1, wherein the third segment has a height greater than the height of the second segment such that there is a spacing between the second segments of the bus bars of any pair of adjacent solar cell sheets facing each other in a direction perpendicular to the substrate sheet.

9. The stack assembly of claim 8, wherein the thickness of the second segment tapers in a direction from the third segment to the first segment.

10. The shingle assembly of claim 1, wherein the third section is a solid bar structure.

11. The shingle assembly of claim 1, wherein a cutout is provided in the third section.

12. The shingle assembly of claim 11, wherein the cutout is a circular or triangular hole structure formed in the third section.

13. The shingle assembly of claim 1, wherein the bus bars on both the top and bottom surfaces of the solar cell sheet are multi-segment bus bars, and wherein the length of the third segment on the top surface of the solar cell sheet is not equal to the length of the third segment on the bottom surface of the solar cell sheet.

14. The shingle assembly of claim 1 wherein the busbar on both the top and bottom surfaces of the solar cell sheet is a multi-segment busbar, the third segment has a face facing away from the substrate sheet formed as a saw-toothed structure, and the facing third segments of two adjacent solar cell sheets contact each other in a rack-and-pinion fashion.

15. The shingle assembly of claim 1, wherein the joined height of the contacted third sections of each pair of adjacent solar cells is greater than or equal to the height of the adhesive.

16. The stack assembly of claim 1, wherein the bus bars on one of the top and bottom surfaces of each of the solar cells are multi-segment bus bars and the bus bars on the other are intermittently arranged multi-segment bus bar structures, wherein in the first direction, the multi-segment bus bar structures are at least aligned with the third segments of the multi-segment bus bars and the spacing portions between the multi-segment bus bar structures are at least aligned with the first segments of the multi-segment bus bars.

17. The shingle assembly of claim 1, wherein the adhesive is not electrically conductive.

18. A solar cell sheet, a plurality of solar cell sheets being sequentially arranged in a shingled manner in a first direction and fixed relative to each other by an adhesive, wherein each solar cell sheet comprises a substrate sheet, one busbar is disposed on each of a top surface and a bottom surface of the substrate sheet, the busbar on at least one of the top surface and the bottom surface is a multi-segment busbar comprising a first segment, a third segment and a second segment connected between the first segment and the third segment, wherein:

19. The solar cell sheet according to claim 18, wherein the second segment and the third segment extend along one longitudinal edge of the base sheet, and the first segment is recessed on its surface from the longitudinal edge toward the other longitudinal edge of the base sheet.

20. The solar cell sheet according to claim 18, wherein the second segment and the third segment extend near one longitudinal edge of the base sheet, and the first segment is recessed on its surface from the direction of extension of the second segment and the third segment further toward the longitudinal edge.

21. The solar cell sheet according to claim 18 or 19, wherein the first section comprises a central section extending parallel to the second direction and a connecting section connecting the central section and the second section.

22. The solar cell sheet of claim 18, wherein the first, second and third sections are equal in width or smaller in width than the third section.

23. The solar cell sheet of claim 18, wherein the width of the first section is less than the width of the third section, and the width of the second section tapers in a direction from the first section to the third section.

24. Solar cell sheet according to claim 23,

25. The solar cell sheet according to claim 18, wherein the third segment has a height greater than that of the second segment, so that there is a space between the second segments of the bus bars facing each other of any pair of adjacent solar cell sheets in a direction perpendicular to the base sheet.

26. The solar cell sheet of claim 25, wherein the thickness of the second section tapers in a direction from the third section to the first section.

27. The solar cell sheet of claim 18, wherein the third section is a solid strip structure.

28. The solar cell piece according to claim 18, wherein a hollow-out portion is disposed on the third section.

29. The solar cell piece of claim 28, wherein the hollowed-out portion is a circular hole structure or a triangular hole structure formed on the third section.

30. The solar cell sheet of claim 18, wherein the busbar lines on the top and bottom surfaces of the solar cell sheet are multi-segment busbar lines, and the length of the third segment on the top surface of the solar cell sheet is not equal to the length of the third segment on the bottom surface of the solar cell sheet.

31. The solar cell sheet according to claim 18, wherein the surface of the third segment facing away from the base sheet is formed in a zigzag structure so that the third segments of the bus bars facing each other of two adjacent solar cell sheets are in contact with each other in a rack-and-pinion manner.

32. The solar cell sheet of claim 18, wherein the thickness of the bus bars is configured such that the junction height of the contacted third sections of each pair of adjacent solar cell sheets is greater than or equal to the height of the adhesive.

33. The solar cell sheet of claim 18, wherein the bus bars on one of the top and bottom surfaces are multi-segment bus bars and the bus bars on the other are intermittently arranged multi-segment bus bar structures, wherein in the first direction, the multi-segment bus bar structures are at least aligned with the third segments of the multi-segment bus bars and the spacing portions between the multi-segment bus bar structures are at least aligned with the first segments of the multi-segment bus bars.

34. A manufacturing method of manufacturing a stack assembly according to any of claims 1-17, characterized in that the manufacturing method comprises the steps of:

35. The method of claim 34, wherein the step of fabricating the plurality of solar cells comprises:

pretreating the whole solar cell;

36. The method of claim 35, wherein the step of pre-treating the entire solar cell sheet comprises:

37. The manufacturing method according to claim 36,

the inner passivation layer is deposited by a thermal oxidation method or a laughing gas oxidation method or an ozonization method or a nitric acid solution chemical method, and is set as a silicon dioxide film layer; and/or

The outer passivation layer is deposited using a PVD, CVD or ALD method.

38. A method according to any of claims 34-37, characterized in that the method does not comprise a step of applying a conductive glue.